4-5 hours?!?! WOW! My hair is about midway down my back and it took about 2 hours...I did highlights for the first time with it yesterday so the entire process took about 3.5 hours...I can't wait to wash it and see how it came out!
The more you do it, the less often you have to do it...I am super picky about my hair and tend to do things a bit more frequently...I relax my hair as well so typically, I do that every 8 weeks then 2 weeks later do the keratin...some times have come out better than others (no idea why) so I have been able to get more time out of some of the treatments...my fear is that the keratin will wear off between relaxing cycles so even if I don't "need" it, I will do it anyway just to be safe.
There are a number of shampoos you can use as long as they are sulfate free...the salon has a few different ones...I HATED the Coppola shampoo...it smelled fine, but I didn't feel like my hair was getting clean...my personal favorite is Thermafuse (my salon carries it and gives me a bottle when I get my keratin treatment done)
Also, nobody tells me to do this and the salon does wash your hair before doing the treatment, but I always do a clarifying shampoo the morning of the treatment...I use Paul Mitchell clarifying shampoo...It could be psychological, but I feel like by getting any build up out of the way, it enables the keratin to soak in more. I don't use that shampoo often because it is not sulfate free...
You are SO going to love having this done! Honestly, it has changed my life (I know that sounds so corny, but it has)...all the things I have always hated about my hair are more or less fixed...I HATED that it took me 45+ minutes to blow out my hair...now it takes 15-20...I HATED that any time there was an OUNCE of humidity in the air or it drizzled out, my hair was a fuzzball...no more! LOVE, LOVE, LOVE it! It is expensive, but if you can afford it - worth EVERY penny! Plus, you spend less on products so in some ways, it balances out